In U.S. Pat. No. 3,707,126 granted Dec. 26, 1972, locking members (61) are disclosed which in closed position engage the end of a gravity gate rack. The locking member is attached to an operating shaft (56) which is rotatable to move the locking member to a vertical position (FIG. 7) allowing the gate to move toward open position. However, the locking member includes a depending leg (61b) which is engaged by an extension from the gate (36) and pivots the locking member into a tripped position resting on the gate where it remains while the gate assumes the full open position.
When the gate is moved toward closed position the locking member is again pivoted by the extension (36) and in closed position the locking member again engages the rack end.
However, if the gate were left in open position and a strong impact were applied to a railway car upon which the outlet is mounted, the locking member could pivot back to the vertical position and not in engagement with the rack end holding the gate in closed position. In this event, the gate could again move to the open position in transit.